Balancer



\ Dec.l6, 1947. B. F. LANGER BALANCER Filed Sept. 28, 1944 2 Sheets-Sheet 1 13 w INVENTOR Bernard F." Langer.

Marian of &L acamotz'ue 2 Patented Dec. 16, 1947 *UNITED STATES PATENT .OFFICE' 2,432,9pv

BALANCER 1 Bernard F. Langer, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa, a corporation of Pennsylvania Application September 28, 1944, Serial No. 556,246

My invention relates, generally, to balancers and, more particularly, to balancers for steam locomotives.

In'atwo cylinder steam locomotive it is impossible even toapproach good balance of the oscillating forces by the methods now used. The reason for this is that the counterbalance weights are put in the wheels ,of the locomotive where their motion is rotational, whereas a large part of the vibrations originate in the reciprocating parts of the driving mechanism, such as the pistons and part of the connecting rods. The usual method of balancing steam locomotives is to put sufiicient counterbalance weights in the wheels to counteract the rotating forces and about half of the reciprocating forces. The other half of the reciprocating force is absorbed by the inertia of the locomotive and results in vibration. An even more serious consequence is that the vertical compohent of the counterweight force has only the rail to react against and causes a fluctuation in the wheel load with each revolution. This fluctuation in wheel load is commonly known as dynamicaugment and is one of the chief limitations tothespeed .of steam locomotives. To give some idea of. themagnitude of this fluctuation, the example might be given of one popular type of high speed locomotive for which the dynamic augment at,10,0 M.. P. I-Listwo-thirds of the wheel load. 1, This means that the rail load of each wheeL-even on smooth straight track, fluctuates between and 1 of its static value during each revolution. I

Anobject of my invention, generally stated, is to provide a locomotive balancer which shall be simple and efficient in operation and which may be economically manufactured and installed.

A more specific object of my invention is to counterbalance the reciprocating force in a steam locomotive.

Another object of my invention is to prevent fluctuation in the wheel load of a locomotive of the reciprocating type.

A further object of my invention is to provide a locomotive balancer which will not increase the unsprung weight of a locomotive.

Still another object of my invention is to provide a balancer which can readily be added to an existing locomotive.

Other objects of my invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of my invention, a hollow shaft or quill surrounds one of 5 Claims. (Cl. 1(i5 -1l)8) the driving axlesofa locomotive and is rotatably mounted in the locomotive frame. The quill is driven by the shaft which it surrounds and it drives 'two other shafts mounted in the frame. Balancing weights are so disposed on these shafts that all the reciprocating force is counterbalanced. V

For a fuller understanding of the nature and objects of my invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a view, partially in plan and partially in section, of a portion of a locomotive structure embodying my invention;

1 Fig. 2 is a view, partially in side elevation and partially in section, of the structure shown in F g- 1 l r Fig. 3 is a vector diagram of the balancing system shown in Figs. land 2;

Fig.4 is a vector diagram of a slightly modified balancing system;

Fig. 5 is a view, in plan, of a modification of the invention;

, Fig. 6 is a view, partially in side elevation and partially in section, of the structure shown in Fi 5;

Fig. 7 is a vector diagram of the balancing sys- ,tem shown in Figs. 5 and 6, and

Fig. 8 is a diagrammatic View showing the location of the reciprocating and the rotating parts of a steam locomotive.

LIn practicing my invention, the rotating forces which are due to the inertia of the side rods, crank pins, etc. are counterbalanced in the usual manner, that is, by means of balance weights placed in the wheels of the locomotive. A novel feature of my system is the method of counterbalancing the reciprocating forces, which may be accomplished by means of the device shown in Figs. land 2. These figures show the application of the device to a steam locomotive of the Pacific (4-6-2) type. There are many difierent ways in which the device could be arranged some of which will be mentioned hereinafter.

Referring to the drawing, the structure shown in Figs. 1 and 2 comprises a portion of a main frame I of a locomotive having driving wheels 2 secured to axles 2' in the usual manner. A hollow cylindrical member 3 surrounds the middle driving axle 2' and rotates in bearing 3 disposed in the locomotive frame I. The member 3 may be comparedto the quill in the well known quill drive utilized on electric locomotives. It is driven by the axle which it surrounds through a flexible coupling 4 which maybe oneof the types usually utilized on electric locomotives. The coupling l, illustrated in the drawings, is similar to one commonly known as a cup-drive. A gear 4 is secured to the outer surface of the cylindrical member 3. The gear 4 drives two other gears 5 and 6, which, in turn, drive shafts 1 and 8, respectively.

The shafts 7 and 8 are mounted in bearings disposed in the main frame I of the locomotive. The gears 4, 5 and 6 all have the same diameter. Thus, the members 3, 1 and 8 comprise a system of shafts mounted in the main frame I which all rotate at a angular velocity equal to that of the driving wheels. As indicated by the arrows in Figure 2, the shaft 3 rotates in the same direction as the wheels, while 1 and 8 rotate in the opposite direction.

The shafts 3, 7 and 8 each have two counterweights mounted on them in angular relation, thereby making a total of six individual weights, 9, I0, H, l2, l3 and [4. As shown in Figure 1, the weights 9, In and H are disposed on one side of the longitudinal center line of the locomotive, and the weights, l 2, l3 and M are disposed on the other side of the center line.

The effect of the three weights which are On one side of the locomotive, for instance the left side, will be considered first. The weight 9 is attached to the shaft 3, weight [0 is attached to the shaft 1 and the weight I I is attached to shaft 8. If all three weights have the same mass, and 9 rotates at twice the radius of either 10 or II, the centrifugal force of 9 is equal to that of II] and II combined. Any combination of masses and radii which makes 9 equivalent to H] and H combined is satisfactory. As may be seen from Fig. 2, weights 9, l0 and II all reach their extreme fore and aft positions at the same instant. However, because of the different directions of rotation, 9 is in its uppermost position when It and II are in their lowermost position. Therefore, the vertical components of the centrifugal forces are cancelled. However, the horizontal components add. Therefore, the net result is a sinusoidally varying, longitudinally directed, reciprocating force exerted on the frame of the locomotive.

On the other side of the locomotive a similar set of three weights l2, I3 and [4 produces another reciprocating force. ship between these forces on each side of the locomotive can be adjusted to any desired value. By correct choice of the magnitude and p ase position of the counterweights it is possible'to counterbalance any system of longitudinal reciprocating forces in the plane of the axle centers both as to forces and moments.

The calculation of the correct magnitude and phase position of the weights is most easily done by means of vectors. In the vector diagram, illustrated in Figure 3, the line ABCD represents a horizontal line perpendicular to the longitudinal axis of the locomotive. The points A, B, C and D are the points at which this line intersects various vertical longitudinal planes in which we are interested. A and D are in the planes of the pistons and connecting rods of the locomotive. B and C are in the planes of the counterweights. The points X show the locations of the driving wheels. The vectors drawn from points A, B, C and D represent. the reciprocating forces in magnitude and phase. The actual forces are the projections of the rotating vectors on a horizontal plane. The vectors rotate counterclockwise.

The vectors L and R represent the inertia forces The phase relationof the left and right pistons and rods. They are apart. B1. and BR are the counterbalance forces required to produce equilibrium. Vector BL=L1+L2 and BR=R1+R2. The equilibrium equations are l-R1=L, (2) R2L2=R, (3) L1 =R1( +b), and (4) R2d=L2(b+d). From these equations we can determine L1, L2, R1 and R2, from which We can find BL and BE in both magnitude and phase.

To take a simple example, let L=R=500 1b. equivalent weight at the rim of the driving wheel and a:b=d=30 inches. (These figures approximate an actual case). Substituting and solving, we get: R1=L2=500 1b. L2=R1=1000 1b.,

alpha=beta=arctan 0.5=2630'.

BL=BR=V l000 +500 =1120 lb. equivalent weight at the wheel rim.

In Fig. 2, weight 9 is shown rotating at a radius about equal to that of the drivin wheel and weights l0 and II have half that radius. Therefore each of the weights 9-! 4 inclusive should weight 560 lb. The angular spacing between any two weights on the same shaft (say weights l0 and 53 on shaft 7) should be 90+2 2630=143. All necessary angular relationships can be found from Fig. 3.

In Figs. 1 and 2 there is illustrated just one of the many forms which a device utilizing the same fundamental principles could take. Some of the more important variations are as follows:

(1) Any two weights on the same shaft, say l0 and IS on shaft 1, could be replaced by three weights on the same shaft, two in the same planes already shown and the third in the plane of the center line of the locomotive. Fig. 4 illustrates how these weights would be arranged. The vectors It and I3 represent the forces from the correspondingly numbered weights of Fig. 1. The vectors I5, I 6 and I! represent the forces from an alternative system of weights. The counterweight E5 of Fig. 4 would be located in the gear 5 of Fig. 1. The co-unterweights l6 and I1 would replace I0 and I3 and be located apart, instead of 143.

(2) Figs. 1 and 2 show a device large enough to counterbalance the whole locomotive with a single unit. A larger number of smaller units could be utilized. This would be particularly applicable to locomotives with four or more driving wheels.

(3) A unit could be built with two, instead of three, rotating shafts. A single unit with two shafts in a horizontal plane would apply a pitching moment to the locomotive when one Weight was up and another down. However, with an even number of such units, the pitching moments could be made to counteract each other.

(4) The two or three shafts comprising a single unit might not lie in the same horizontal plane.

(5) It is possible to use any desired combination of the old method of balancing and the one herein described in case the full benefits of the new method are not required.

(6) It is not necessary to have one of the balance shafts enclosing an axle as does shaft 3 in Figs. 1 and 2. A complete unit consisting of two or three balance shafts could be located between two axles and be driven from one of the axles.

(7) The gears used to drive the balance shafts could also be utilized to transmit tractive effort from one axle to another and thus eliminate side rods.

(8) Similar devices could be devised for use on three or four cylinder steam locomotives.

A further modification of my invention is illustrated in Figs. 5 and 6, in which like parts are designated by the same reference characters as inFigs. 1 and 2. The balancing device illustrated in'Figs. 5 and6 is similar to the one shown in Figs. 1 and 2, with the exception that the counterweights which rotate in the same direction as the wheels are located in the wheels themselves, instead of on a separate shaft, such as the shaft or quill 3. Thus, the balance Weights are located in four different planes, instead of in two planes as in the structure hereinbefore described. The method of obtaining correct cross balance with the weights in four planes is explained in the following analysis:

In Figure 7 the line ABCDEF runs across the locomotive through th center of the axle being balanced. A and F are in the planes of the left and right connecting rods. B and E are in the planes of the wheels. C and D are in the planes of the counterweights 2|, 22, 23, and 24 of Fig ures 5 and 6.

The vectors at points B, C, D, and E represent in magnitude and direction components of the centrifugal forces of counterweights rotating about those points. The vectors at A and F represent the phase positions of thereciprocating forces from the pistons and connecting rods, but the magnitudes of these forces are the projections of the vectors on a horizontal plane. The direction of rotation of the vectors is shown by arrows. The equilibrium equations are:

The solution of these equations is:

ase

ara

To take a simple example, suppose the reciproeating force is 500 lbs. equivalent weight at the radius of a driver on each side of the locomotive and a=b=d= inches. U for each axle is then for a 4-6-2 type locomotive. Then W=104 lbs., G=20.9 lbs., H=167 lbs., and V=83.5 lbs. The combined effects of weights 2| and 22 must equal the vector sum of forces H and V.

If the weights rotate at a radius about that of a driver each weight is 6 6 is also more compact than the one shown in Figs. 1 and 2.

From the foregoing description it is apparent that some of the advantages of my invention are decreased vibration of the locomotive and decreased forces applied by the wheels to tracks and bridgesthereby permitting the locomotive to operate at a higher speed. Furthermore, the balancing device, herein described, does not add to the unsprung weight of the locomotive, since it is mounted in the locomotive frame and not on the locomotive axles, as is the case with previously known balancing devices.

Since numerous changes may be made in the above-described construction and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intendedthat all matter contained in the foregoingdescription or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim as my invention:

1. In a locomotive having a frame, reciprocating pistons, side rods, crank pins, driving wheels and axles therefor, in combination, a rotatably mounted quill surrounding one of the axles, means for rotating said quill, shafts disposed on opposite sides of said quill and driven thereby in a direction opposite to that of the axles, said shafts being rotatably mounted in the locomotive frame and supported thereby, a plurality of balancing weights of predetermined magnitude and phase position rotated by said shafts at the same angular velocity as the driving wheels to counterbalance the reciprocating forces of the locomotive, and additional balancing Weights of predetermined magnitude rotated in the same direction and at the same angular velocity as the wheels and cooperating with said first-named weights in counterbalancing the reciprocating forces.

2. In a locomotive having a frame, reciprocating pistons, side rods, crank pins, driving wheels and aXles therefor, in combination, a quill surrounding one of the axles and rotatably mounted in the locomotive frame, means for rotating said quill at the same speed as the axle which it surrounds, a gear secured to said quill, shafts disposed on opposite sides of said gear and driven thereby at the same speed as said gear and in a direction opposite to that of the axles, said shafts being rotatably mounted in the locomotive frame and supported thereby, a plurality of balancing weights of predetermined magnitude and phase position rotated by said shafts to counterbalance the reciprocating forces of the locomotive, and additional balancing weights of predetermined magnitude rotated in the same direction and at the same angular velocity as the Wheels and cooperating with said first-named weights in counterbalancing the reciprocating forces.

3. In a locomotive having a frame, reciprocating pistons, side rods, crank pins, driving wheels and axles therefor, in combination, a quill surrounding one of the axles and rotatably mounted in the locomotive frame, means for flexibly driving said quill from said axle, shafts disposed on opposite sides of said quill and connected in driving relation therewith, said shafts being rotatably mounted in the locomotive frame and rotated in a direction opposite to that of the axles, aplurality of balancing weights of predetermined magnitude and phase position rotated by said shafts at the same angular velocity as the driving wheels to counterbalance the reciprocating forces of the locomotive, and additional balancing weights of predetermined magnitude rotated in the same di* rection and at the same angular velocity as the wheels and cooperating with said first-named weights in counterbalancing the reciprocatin forces.

'4. In a locomotive having a frame, reciprocating pistons, side rods, crank pins, driving wheels and axles therefor, in combination, a quill surrounding one of the axles and rotatably mounted in the locomotive frame, means for rotating said quill, shafts disposed on opposite sides of said 'quill and driven therefrom in a direction opposite to that of the axles, said shafts being rotatably mounted in the locomotive frame and supported thereby, a plurality of balancing weights of predetermined magnitude and phase position rotated by said shafts at the same angular velocity as the wheels to counterbalance the reciprocating forces of the locomotive, and additional balancing Weights of predetermined magnitude and phase position secured to said quill and cooperating with said first-named Weights in counterbalancing the reciprocating forces.

.5. In a locomotive having a frame, reciprocating pistons, side rods, crank pins, driving wheels and axles therefor, in combination, a quill sur- 8 rounding one of said axles and rotatably mounted in the locomotive frame, means for rotating said quill at the same speed as the axle which it sunrounds, shafts disposed on opposite sides of said quill and driven thereby .in a direction opposite to that of the axles, said shafts being rotatably mounted in the locomotive frame and supported thereby, a plurality of balancing weights of predetermined magnitude and phase position rotated by said shafts at the same angular velocity as the driving wheels to counterbalance the reciprocatin'g forces of the locomotive, and additional balancing weights of predetermined magnitude secured to said wheels and cooperating with said first-named weights in counterbalancing the reciprocating forces.

BERNARD F. LANGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Thearle Oct. 20, 1931 Number 

